Employee Benefit Obligations (Details 4) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Pension Plans
Employee Benefit Obligations
Total assets	$ 1,303.3	$ 1,435.2	$ 1,386.9
U.S.
Employee Benefit Obligations
Total assets	987.6	1,098.0	1,109.5
U.S. | Cash and cash equivalents
Employee Benefit Obligations
Total assets	68.9	89.6
U.S. | Consumer discretionary Securities
Employee Benefit Obligations
Total assets	46.6	53.8
U.S. | Industrials corporate equity securities
Employee Benefit Obligations
Total assets	61.2	58.7
U.S. | Financials corporate equity securities
Employee Benefit Obligations
Total assets	37.4
U.S. | Healthcare Corporate equity securities
Employee Benefit Obligations
Total assets	25.9
U.S. | Information technology corporate equity securities
Employee Benefit Obligations
Total assets	53.2	57.5
U.S. | Other corporate equity securities
Employee Benefit Obligations
Total assets	52.5	151.0
U.S. | U.S. government and agency securities-FHLMC mortgage backed securities
Employee Benefit Obligations
Total assets	14.4	14.7
U.S. | U.S. government and agency securities-FNMA mortgage backed securities
Employee Benefit Obligations
Total assets	55.9	49.9
U.S. | U.S. government and agency securities-Treasury bonds
Employee Benefit Obligations
Total assets	31.7
U.S. | U.S. government and agency securities-Other
Employee Benefit Obligations
Total assets	23.9	62.2
U.S. | Corporate bonds and notes-Financials
Employee Benefit Obligations
Total assets	91.5	96.5
U.S. | Corporate bonds and notes-Industrials
Employee Benefit Obligations
Total assets	21.1
U.S. | Corporate bonds and notes-Utilities
Employee Benefit Obligations
Total assets	21.5	33.4
U.S. | Corporate bonds and notes-Private placement
Employee Benefit Obligations
Total assets	37.3	44.8
U.S. | Corporate bonds and notes-Other
Employee Benefit Obligations
Total assets	84.6	113.5
U.S. | International Commingled Funds
Employee Benefit Obligations
Total assets	66.6	88.2
U.S. | Other Commingled Funds
Employee Benefit Obligations
Total assets	66.3	53.6
U.S. | Limited partnerships and other
Employee Benefit Obligations
Total assets	127.1	130.6
U.S. | Level 1
Employee Benefit Obligations
Total assets	322.8	359.4
U.S. | Level 1 | Cash and cash equivalents
Employee Benefit Obligations
Total assets	2.9	0.9
U.S. | Level 1 | Consumer discretionary Securities
Employee Benefit Obligations
Total assets	46.6	53.8
U.S. | Level 1 | Industrials corporate equity securities
Employee Benefit Obligations
Total assets	61.2	58.7
U.S. | Level 1 | Financials corporate equity securities
Employee Benefit Obligations
Total assets	37.4
U.S. | Level 1 | Healthcare Corporate equity securities
Employee Benefit Obligations
Total assets	25.9
U.S. | Level 1 | Information technology corporate equity securities
Employee Benefit Obligations
Total assets	53.2	57.5
U.S. | Level 1 | Other corporate equity securities
Employee Benefit Obligations
Total assets	34.1	116.6
U.S. | Level 1 | U.S. government and agency securities-Treasury bonds
Employee Benefit Obligations
Total assets	31.7
U.S. | Level 1 | U.S. government and agency securities-Other
Employee Benefit Obligations
Total assets	11.7	49.1
U.S. | Level 1 | International Commingled Funds
Employee Benefit Obligations
Total assets	15.9	19.5
U.S. | Level 1 | Other Commingled Funds
Employee Benefit Obligations
Total assets	2.2	3.3
U.S. | Level 2
Employee Benefit Obligations
Total assets	602.1	675.6
U.S. | Level 2 | Cash and cash equivalents
Employee Benefit Obligations
Total assets	66.0	88.7
U.S. | Level 2 | Other corporate equity securities
Employee Benefit Obligations
Total assets	18.4	34.4
U.S. | Level 2 | U.S. government and agency securities-FHLMC mortgage backed securities
Employee Benefit Obligations
Total assets	14.4	14.7
U.S. | Level 2 | U.S. government and agency securities-FNMA mortgage backed securities
Employee Benefit Obligations
Total assets	55.9	49.9
U.S. | Level 2 | U.S. government and agency securities-Other
Employee Benefit Obligations
Total assets	12.2	13.1
U.S. | Level 2 | Corporate bonds and notes-Financials
Employee Benefit Obligations
Total assets	91.5	96.5
U.S. | Level 2 | Corporate bonds and notes-Industrials
Employee Benefit Obligations
Total assets	21.1
U.S. | Level 2 | Corporate bonds and notes-Utilities
Employee Benefit Obligations
Total assets	21.5	33.4
U.S. | Level 2 | Corporate bonds and notes-Private placement
Employee Benefit Obligations
Total assets	37.3	44.8
U.S. | Level 2 | Corporate bonds and notes-Other
Employee Benefit Obligations
Total assets	84.6	113.5
U.S. | Level 2 | International Commingled Funds
Employee Benefit Obligations
Total assets	50.7	68.7
U.S. | Level 2 | Other Commingled Funds
Employee Benefit Obligations
Total assets	64.1	50.3
U.S. | Level 2 | Limited partnerships and other
Employee Benefit Obligations
Total assets	64.4	67.6
U.S. | Level 3
Employee Benefit Obligations
Total assets	62.7	63.0	$ 51.9
U.S. | Level 3 | Limited partnerships and other
Employee Benefit Obligations
Total assets	62.7	63.0
Canada. | Level 2
Employee Benefit Obligations
Total assets	37.3	47.1
Canada. | Level 2 | Equity commingled funds
Employee Benefit Obligations
Total assets	3.0	3.9
Canada. | Level 2 | Fixed income commingled funds
Employee Benefit Obligations
Total assets	27.5	34.5
Canada. | Level 2 | Fixed income securities
Employee Benefit Obligations
Total assets	6.8	8.7
United Kingdom. | Level 2
Employee Benefit Obligations
Total assets	272.0	285.4
United Kingdom. | Level 2 | Cash and cash equivalents
Employee Benefit Obligations
Total assets	10.9
United Kingdom. | Level 2 | Equity commingled funds
Employee Benefit Obligations
Total assets	54.4	71.3
United Kingdom. | Level 2 | Fixed income commingled funds
Employee Benefit Obligations
Total assets	174.0	174.1
United Kingdom. | Level 2 | Absolute return funds
Employee Benefit Obligations
Total assets	24.5	17.2
United Kingdom. | Level 2 | Alternative investments
Employee Benefit Obligations
Total assets	$ 8.2	$ 22.8